Great Lurking One

While adventuring or living in the Underdark,a Aboleth has made you its slave. In exchange for it giving you a infinitesimally minuscule amount of its power and knowledge,your new master commands you to adventure,so it can learn more thru you. Everything you see,hear,and know,is also learned by your master,via the gemstone it implanted in your forehead. You retain most of your free will,but your masters influence commands you to seek knowledge wherever you go,and makes any thoughts of disobedience nonexistent. 

(l wanted to give this subclass the telepathy spell,but i couldn't if l wanted to share it,so feel free to add it in yourself on paper)

Expanded Spell List

The Great Lurking One lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Great Lurking One Expanded Spells

Spell Level	Spells
1st	Dissonant Whispers, Tasha's Hideous Laughter
2nd	Detect Thoughts, Phantasmal Force
3rd	Clairvoyance, Sending
4th	Dominate Beast, Evard's Black Tentacles
5th	Dominate Person, Telekinesis

Scion of the Awakened Mind

Starting at 1st level, your alien knowledge gives you the ability to touch the minds of other creatures. You can communicate telepathically with any creature you can see within 30 feet of you. You don't need to share a language with the creature for it to understand your telepathic utterances, but the creature must be able to understand at least one language.

You can also telepathically communicate with any aberration, beast, elemental, or monstrosity that has an innate swimming speed, while it is within 120 feet of you. The creature can understand you and can respond telepathically.

Fathomless Soul

At 6th level, your patron grants you greater abilities. You gain the following benefits:
• You can breathe both air and water.
• You gain a swimming speed equal to your walking speed.
• You gain resistance to cold damage.

Thought Shield

Starting at 10th level, your thoughts can't be read by telepathy or other means unless you allow it. You also have resistance to psychic damage, and whenever a creature deals psychic damage to you, that creature takes the same amount of damage that you do.

Psionic Lexicon

Also at 10th level, you learn to touch the psionic energy of other minds so that you understand all spoken languages. Moreover, any creature that can understand a language can understand what you say.

Enthralled by the Depths

At 14th level, you gain the ability to infect a humanoid's mind with the alien magic of your patron. You can use your action to touch an incapacitated humanoid. That creature is then charmed by you until a Remove Curse spell is cast on it, the charmed condition is removed from it, or you use this feature again.

You can communicate telepathically with the charmed creature as long as the two of you are on the same plane of existence.

You can also call upon your Master for aid. As an action, you choose a point within 30 feet of you where your patron tears through reality, manifesting a measure of its thalassic grandeur. You can direct a barrage of spectral tentacles to issue forth and strike up to five creatures you can see within 30 feet of the manifestation point. Each target must make a Dexterity saving throw against your spell save DC. On a failed save, the creature takes 6d10 cold or lightning damage (your choice) and is knocked prone. On a successful save, it takes half as much damage and is not knocked prone. The tentacles then vanish.

Your Master won't aid you in this way again until you finish a long rest.